CN110794212A

CN110794212A - Harmonic detection device based on ARM

Info

Publication number: CN110794212A
Application number: CN201810859874.0A
Authority: CN
Inventors: 张晓彤; 张坤昌; 马童育
Original assignee: Northwest A&F University
Current assignee: Northwest A&F University
Priority date: 2018-08-01
Filing date: 2018-08-01
Publication date: 2020-02-14

Abstract

The invention discloses an ARM-based harmonic detection device, which belongs to the technical field of electric power engineering and mainly comprises a voltage transformer, a current transformer, a phase-locked loop, an anti-aliasing filter, an addition circuit, an AD conversion module, an ARM module, a keyboard and an LCD (liquid crystal display).

Description

Harmonic detection device based on ARM

Technical Field

The invention relates to a harmonic detection device based on an ARM (advanced RISC machine), belonging to the technical field of electric power engineering.

Background

With the continuous development of power grid technology, a large amount of electricity is widely used for electronic equipment and nonlinear loads, so that harmonic pollution is gradually worsened, the power supply reliability of a power system is seriously influenced, and even an accident that the electricity is a system is caused. To ensure that electricity is a safe and economical operation of the system, it is critical that the harmonics be analyzed and detected in real time. The invention develops a harmonic detection device based on ARM.

Disclosure of Invention

Aiming at the defects, the invention provides a harmonic detection device based on ARM.

The invention is realized by the following technical scheme: the utility model provides a harmonic detection device based on ARM, is mainly by voltage transformer, current transformer, phase-locked loop, anti-aliasing filter, adder circuit, AD conversion module, ARM module, keyboard and LCD display screen and constitutes its characterized in that: the voltage transformer and the current transformer are connected with the anti-aliasing filter, the voltage transformer is connected with the phase-locked loop, the phase-locked loop is connected with the AD conversion module, the anti-aliasing filter is connected with the adding circuit, the adding circuit is connected with the AD conversion module, the AD conversion module is connected with the ARM module, and the keyboard and the LCD display screen are connected with the ARM module.

The anti-aliasing filter is an anti-aliasing second-order low-pass filter, a peripheral circuit consists of four resistors and two capacitors, the cut-off frequency is 2KHz, the working voltage of an A/D conversion chip is 0-5V, the voltage value output by a mutual inductor needs to be improved by 2.5V through an addition circuit, the designed addition circuit can change the voltage into 0-5V, the power grid frequency needs to be measured in real time, the AC signal can be converted into a square wave signal by adopting a comparator LM324, and the square wave signal with the same frequency as the input voltage signal is obtained and then sent to a phase-locked frequency doubling circuit.

The ARM module is provided with a communication interface, a JTAG debugging interface, an SDRAM, a FLASH memory and an SD card interface, a system working clock is a 12MHz crystal oscillator, the working clock of a microprocessor is provided by an on-chip phase-locked loop circuit with the frequency multiplication being 533MHz, the S3C6410 system and other application systems adopt a serial interface circuit to carry out ingenious short-distance bidirectional serial communication, and a reset circuit can complete two reset modes: resetting when the system is powered on and resetting a user key when the system works; the JTAG interface can access all components in the chip and debug and program the system, a direct current-direct current converter with the voltage range of 1.2V-5V is arranged in a power circuit, and the power circuit can meet the power supply of TOP64105V/2A and other peripheral circuits needing 1.2V power supply.

The invention has the advantages that: the harmonic detection device based on the ARM has high measurement precision and real-time performance and can reach the standard of harmonic detection in a power grid.

Drawings

FIG. 1 is a schematic diagram of the system of the present invention.

In the figure, the device comprises a voltage transformer 1, a current transformer 2, a current transformer 3, a phase-locked loop 4, an anti-aliasing filter 5, an adding circuit 6, an AD conversion module 7, an ARM module 8, a keyboard 9 and an LCD display screen.

Detailed Description

The utility model provides a harmonic detection device based on ARM, is mainly by voltage transformer 1, current transformer 2, phase-locked loop 3, anti-aliasing filter 4, adder circuit 5, AD conversion module 6, ARM module 7, keyboard 8 and LCD display screen 9 constitute, its characterized in that: the voltage transformer 1 and the current transformer 2 are connected with the anti-aliasing filter 4, the voltage transformer 1 is connected with the phase-locked loop 3, the phase-locked loop 3 is connected with the AD conversion module 6, the anti-aliasing filter 4 is connected with the adding circuit 5, the adding circuit 5 is connected with the AD conversion module 6, the AD conversion module 6 is connected with the ARM module 7, and the keyboard 8 and the LCD display screen 9 are connected with the ARM module 7.

The anti-aliasing filter 4 is an anti-aliasing second-order low-pass filter, the peripheral circuit consists of four resistors and two capacitors, the cut-off frequency is 2KHz, the working voltage of the A/D conversion chip is 0-5V, the voltage value output by the mutual inductor needs to be increased by 2.5V through the addition circuit, the designed addition circuit can change the voltage into 0-5V, the power grid frequency needs to be measured in real time, the AC signal can be converted into a square wave signal by adopting the comparator LM324, and the square wave signal with the same frequency as the input voltage signal is obtained and then sent to the phase-locked frequency doubling circuit.

The ARM module 7 is provided with a communication interface, a JTAG debugging interface, an SDRAM, a FLASH memory and an SD card interface, a system working clock is a 12MHz crystal oscillator, a working clock of a microprocessor is provided by an on-chip phase-locked loop circuit with the frequency multiplication being 533MHz, an S3C6410 system and other application systems adopt a serial interface circuit to carry out ingenious short-distance bidirectional serial communication, and a reset circuit can complete two reset modes: resetting when the system is powered on and resetting a user key when the system works; the JTAG interface can access all components in the chip and debug and program the system, a direct current-direct current converter with the voltage range of 1.2V-5V is arranged in a power circuit, and the power circuit can meet the power supply of TOP64105V/2A and other peripheral circuits needing 1.2V power supply.

When the device works, firstly, a detection electrode is used for collecting voltage and current signals in a power system, a GCT-201B current transformer and a GPT-206B voltage transformer are adopted, then electric signals are sent to a signal conditioning circuit to be processed to obtain signals after filtering and amplitude modulation, analog signals are converted into digital signals through A/D conversion, meanwhile, a phase-locked loop ensures that the sampling frequency and the signal frequency are the same to realize synchronous sampling of the signals, and finally, an ARM11S3C6410 processor which takes TOP6410 as a hardware platform processes and reads the conversion result to complete data operation of an algorithm which combines Fourier transform and wavelet transform of signal windowing, and the processor stores the data and the operation result through a set program and visually displays the analysis result on a liquid crystal display screen through a human-computer interaction interface.

It will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in the embodiments described above without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims.

Claims

1. The utility model provides a harmonic detection device based on ARM, is mainly by voltage transformer, current transformer, phase-locked loop, anti-aliasing filter, adder circuit, AD conversion module, ARM module, keyboard and LCD display screen and constitutes its characterized in that: the voltage transformer and the current transformer are connected with the anti-aliasing filter, the voltage transformer is connected with the phase-locked loop, the phase-locked loop is connected with the AD conversion module, the anti-aliasing filter is connected with the adding circuit, the adding circuit is connected with the AD conversion module, the AD conversion module is connected with the ARM module, and the keyboard and the LCD display screen are connected with the ARM module.

2. The ARM-based harmonic detection apparatus of claim 1, wherein: the anti-aliasing filter is an anti-aliasing second-order low-pass filter, a peripheral circuit consists of four resistors and two capacitors, the cut-off frequency is 2KHz, the working voltage of an A/D conversion chip is 0-5V, the voltage value output by a mutual inductor needs to be improved by 2.5V through an addition circuit, the designed addition circuit can change the voltage into 0-5V, the power grid frequency needs to be measured in real time, the AC signal can be converted into a square wave signal by adopting a comparator LM324, and the square wave signal with the same frequency as the input voltage signal is obtained and then sent to a phase-locked frequency doubling circuit.

3. The ARM-based harmonic detection apparatus of claim 1, wherein: the ARM module is provided with a communication interface, a JTAG debugging interface, an SDRAM, a FLASH memory and an SD card interface, a system working clock is a 12MHz crystal oscillator, the working clock of a microprocessor is provided by an on-chip phase-locked loop circuit with the frequency multiplication being 533MHz, the S3C6410 system and other application systems adopt a serial interface circuit to carry out ingenious short-distance bidirectional serial communication, and a reset circuit can complete two reset modes: resetting when the system is powered on and resetting a user key when the system works; the JTAG interface can access all components in the chip and debug and program the system, a direct current-direct current converter with the voltage range of 1.2V-5V is arranged in a power circuit, and the power circuit can meet the power supply of TOP64105V/2A and other peripheral circuits needing 1.2V power supply.